Laparoscopic Adrenalectomy: The Transperitoneal Approach

Access: Patient Position and Trochar Placement

The positioning of the patient is vital in LA. A well-positioned patient can facilitate access to the adrenal gland and improve ergonomics for the surgeon, while a poorly positioned patient can limit operative access, cause difficulties in trochar placement and frustration to the surgeon. The keys to the patient positioning are: (1) maximal distraction of the distance between the costal margin and iliac crest in the lateral decubitus position; (2) stable and secure support of the patient to allow table rotation and movement, and avoid loss of position intra-operatively; and (3) adequate protection of all pressure points.

After induction of general anesthesia, the patient is placed in the lateral decubitus position with the side of the adrenal lesion facing up. If a beanbag is used, it should be placed under the patient before induction. Alternatively, the lateral decubitus position can be maintained with side supports. Before securing the patient in that position, the patient is positioned with the anterior superior iliac spine over the break point of the table and the table flexed in an inverted “V” position to allow maximal distraction of the space between the costal margin and iliac crest. This angle varies between individuals. Once in a satisfactory position, the patient position is secured with the beanbag suctioned or side supports tightened, ensuring that these supports do not encroach into the operative field.

A soft axillary roll, or a liter bag of fluid, should be placed under the axilla to relieve pressure. The lateral malleolus and lateral peroneal nerve of the bottom leg should be padded. A pillow is placed between the legs to support the top leg. Additional tape can be used to further secure the patient to the table, especially to prevent rotation of the upper chest and legs. The shoulder of the uppermost arm should be at least 90° from the torso, and can be rested on a pillow or arm brace.

The first port is placed 2–4 fingerbreadths below the costal margin, along the anterior axillary line. A cut down is performed with entry into the peritoneal cavity under direct vision. A balloon port is used to facilitate a seal. Following pneumoperitoneum at 12–15 mmH₂O with CO₂, the working ports can be inserted under direct vision on either side of the camera port, with at least 5 cm distance between ports to allow adequate triangulation. At least one of these working ports should be a 10-mm port to allow for passage of a vascular stapling device if required. Alternatively, two 5-mm ports can be used with conversion to a 10-mm port as required. A fourth, 12-mm, port is usually required for a liver retractor for a right LA.

Right LA

The right lobe of the liver is mobilized by dividing the right triangular ligament and the liver retracted medially with a fan or paddle retractor via an epigastric port. Care should be taken to avoid avulsion of hepatic accessory veins draining from the caudate lobe directly into the IVC [23, 24]. With the right hepatic lobe retracted, the IVC, adrenal lesion and right kidney should be identified before proceeding.

The plane between the medial edge of the adrenal gland and the lateral edge of the IVC is developed, and it is within this plane that the right adrenal vein is expected to be encountered. The plane is developed along the entire medial border of the gland, as posteriorly as the psoas muscle. Anatomical variations such as drainage into accessory hepatic veins or duplicate right adrenal veins have been reported in 13 % of autopsy series, and therefore care should still be taken in dissecting this plane after division of a right adrenal vein [23, 24]. The vein can be ligated by a variety of methods including an energy-sealing device, clips and vascular stapler, depending on the size [25]. As the dissection of this plane proceeds inferiorly, an accessory branch of the renal artery may be seen heading toward the superior renal pole. It should be preserved to avoid infarction of the renal pole. The inferior limb of the adrenal gland may extend as far inferior as the renal hilum and therefore inadvertent injury to the hilar vessels must be avoided during dissection of a low lying limb.

Once the medial adrenal border is defined, dissection can be continued laterally by separating the inferior adrenal border from the superior renal pole, and superiorly by lifting the adrenal gland off the psoas muscle. Separating the gland from the lateral and superior attachments completes the dissection. This part of the dissection is best done with an energy sealing device as the arteries feed into the adrenal gland from its periphery [25].

Left LA

The left LA begins with defusing the spleen by dissecting the small peritoneal attachments from the greater omentum. The plane between the splenic flexure, mesocolon and the kidney is developed and the spleen is mobilized by dividing the lienorenal ligament, and continuing the dissection onto the posterior surface of the pancreatic tail and splenic vessels. The diaphragmatic attachments of the spleen are divided superiorly until the fundus of the stomach is in view, and the spleen medially rotated without retraction. The retroperitoneum is opened along the medial border of the adrenal gland, and the left adrenal vein identified. A guide to this vein is the inferior phrenic vein, which drains into the left adrenal vein before it drains into the left renal vein. Alternatively, the left renal vein could be a guide to the adrenal vein.

Once the adrenal vein has been ligated, the gland can be dissected off its attachments from the superior renal pole and psoas muscle in a medial-to-lateral and inferior-to-superior manner, with an energy-sealing device.

Special Considerations

While observing the standard principles of LA as described above, additional technical pointers may further facilitate excision of particular types of lesions. When excising a pheochromocytoma, it is useful to “dissect the patient away from the tumor”, and avoid handling the tumor directly. Excessive pressure on the tumor may cause a surge of catecholamine release into the circulation resulting in hemodynamic lability. The gland should never be grasped; if necessary, periadrenal fat, the disconnected vein or retroperitoneal fascia may be used as “handles” to gently retract the tumor. Early ligation of the adrenal vein also helps minimize catecholamine release.

In resections of metastatic deposits in adrenal glands, it is important to observe the oncological principle of en bloc resection to include the peri-adrenal fat [26•]. Not only is it oncologically sound, an en bloc resection also avoids having to dissect the gland through malignancy-induced inflammatory adhesions. Although it is usually desirable to control the adrenal vein early in the procedure and start the dissection on the medial side, it may be difficult to do so with large tumors. In such cases, mobilization of the lateral and inferior borders of the gland may facilitate access to the medial border for ligation of the adrenal vein. In cases of large spleens, a fourth port may be required for additional retraction.

Complications

There is a large body of evidence to support laparoscopic adrenalectomy as the gold standard for surgery to remove the adrenal gland. Indeed, benefits such as reduced pain, reduced ileus, reduced perioperative morbidity, less blood loss, earlier return to full activity and improved cosmesis are all clearly seen with the laparoscopic approach compared with the open approach in adrenal surgery.

By far the most common intraoperative complication is hemorrhage. The cumulative rate is up to 40 % of overall complications [27]. Laparoscopic control of this can range from increasing insufflation pressures, simple electrocautery and placement of endoscopic clips and ligatures, but in some rare cases, conversion to an open laparotomy is required. Conversion to open surgery was documented to be as high as 6 % in some early studies [28] during the evolution of the technique to a low of only 0.6 % in a recent large study by Kulis and colleagues [29•].

Other intraoperative morbidity that arises includes injury to viscera and solid organs including the kidney, liver and spleen [30]. Assalia and Gagner [27] quoted a intraoperative complication rate of 9.5 % in their review of the literature in 2004, although the accuracy of this figure was difficult to ascertain due to a lack of a standardized definition.

Although both LA and OA are reported to have low mortality rates, the mortality rate associated with LA was significantly lower (0.6 vs. 1.3 %, p < 0.0001) [2•]. Similarly, LA has been consistently found to have a lower morbidity rate than OA (4.5 vs. 7.8 %, p < 0.0001), and shorter length of stay (3.2 vs. 5.2 days, p < 0.0001) [2•, 31, 32].

Outcomes Comparison Between Open and Laparoscopic Adrenalectomy

The one aspect of LA that was variable between studies was that of total operative time. There is a trend towards a longer operative time in the laparoscopic approach compared to the open approach amongst early adopters of the technique. However, with the advancement of technology and modernization of laparoscopy together with experience and familiarity with the procedure, the trend has shifted to a shorter operative time [21], and in a recent case series of 306 patients by Kulis and colleagues [29•], the operative time has been slashed to <100 min.

In the comparative studies of LA and OA, LA patients also benefited from an earlier discharge from hospital compared to OA patients and has the clear advantage of a earlier return to a normal diet [33] and earlier resumption of normal activity [34]. The benefit of a laparoscopic approach was further underlined in the comparative studies that measured analgesic requirements, showing LA patients requiring far less analgesics compared to their OA counterparts [35, 36, 37].

The long-term operative morbidity is indeed also lower for LA patients, no doubt benefiting from much smaller wounds. In series which had long-term follow-up, the finding was that patients underwent OA for various reasons had a much higher wound complication rate, up to 54 % in a posterior OA group [36]. This finding is supported by data from Imai et al. [35], with a late wound complication rate of 47.5 % in the OA group compared to zero in the LA group.

The lateral transperitoneal approach is our preferred method of LA. It affords familiar anatomical landmarks and provides a larger working space [17, 38, 39].

Outcomes Analysis for Malignant Adrenal Masses

Single Port Access Laparoscopic Adrenalectomy

Evolving technology has allowed the evolution of single incision laparoscopic surgery (SILS) to be employed in various procedures. Articulated instruments and a specialized laparoscope introduced through a single, albeit larger, laparoscopic port are used. Post-operative benefits include reduced analgesic requirements and improved cosmesis with a single scar [48, 49]. However, the downsides include spatial unfamiliarity, the requirement and subsequent cost for specialized instruments as well as port-site congestion despite the use of articulated instruments to prevent operator and assistant interference.

In the case of SILS adrenalectomy, the technique was first described by Castellucci and colleagues in 2008 [50]. There have been several subsequent reports and series examining the efficacy of SILS in adrenalectomy. In most instances, an additional port is sometimes required to aid in organ retraction. Rane et al. [51] reviewed the available literature and examined the outcomes in SILS adrenalectomy versus the conventional laparoscopic approach. They concluded that operative time was longer in SILS compared to the conventional laparoscopic approach, but analgesic requirements were reduced post-operatively. One significant hurdle was the longer mean operative time, a reflection of multiple factors both at the operator and instrument level, factors that may improve with familiarity and newer technology.

Laparoscopic Retroperitoneal Adrenalectomy

Given the normal location of the adrenal glands in the upper retroperitoneal space, a laparoscopic retroperitoneal (LR) approach has been viewed by some as an evolution of the traditional transperitoneal LA approach. Certainly, a direct retroperitoneal approach confers faster operative access without the need to traverse the peritoneal cavity and avoiding intra-peritoneal organs. Without the need to enter the peritoneal cavity and irritate abdominal viscera, the risk of ileus and need for analgesia is potentially further diminished.

A large series of 560 procedures by Walz et al. [52] demonstrated that, in experienced hands, LR adrenalectomy is safe and potentially faster than a trans-peritoneal approach. Lee and colleagues [53] demonstrated that a LR approach elevated the peri-operative benefits initially demonstrated with the advent of transperitoneal LA versus OA. Indeed, LR adrenalectomy has also been shown to be effective in Conn’s adenomas and hyperplasia [54] and in pheochromocytoma [55, 56].

Robotic Adrenalectomy

The advent of robotic surgery and its purported benefits with a tremor-free three-dimensional imaging, improved operator ergonomics, improved instrument manoeuvrability and improved cosmesis compared to conventional open surgery have been documented since being described in the early 2000s [57, 58]. Disadvantages compared to traditional laparoscopic surgery include the lack of tactile feedback, especially when approaching a fragile organ such as the adrenals, longer operating times, and the significant cost associated with robotic surgery. Brunaud and colleagues [59] compared the advantages and disadvantages of robotic adrenalectomy (RA) with the traditional transperitoneal LA. In a large series of 109 patients, with 50 undergoing RA and 59 undergoing LA, they found that RA was associated with lower blood loss and longer operating times which ceased to be significant once a learning curve had been overcome. They found that RA was approximately 2.3 times more costly that traditional LA but, like other studies, the cost-benefit ratio may improve with multi-specialty use of the robot and sharing of expenses at larger centers [59, 60].